Handout 3 (1-2) Chpater’s 28-4 and 30-3 Asteroids, Comets, and Meteroroids And Star Groups Handout 28-4 Asteroids, Comets, and Meteoroids 1. In addition to the sun, planets, and their moons, what occupies the space in our solar system? • The solar system includes million of smaller bodies; some are tiny bits of dust or ice; others are as large as small moons. 2. What are asteroids? • fragments of rock that orbit the sun 3. Most asteroids are found in the asteroid belt located • between the orbits of Mars and Jupiter. 4. The composition of asteroids is similar to that of the • inner planets. 5. For what reason do many astronomers think that asteroids in the asteroid belt were not able to form a planet? • because of the strong gravitational force of Jupiter 6. What is a comet? • a small body of ice, rock, and cosmic dust that orbits the sun 7. A comet’s spectacular tail forms when • sunlight changes the comet’s ice to gas. Matching 8-13 8. meteor 9. meteor shower 10 iron meteorite . 11 stony meteorite . a. a large number of meteoroids entering Earth’s atmosphere in a short period of time. b. a bright streak of light that results when a meteoroid burns up in Earth’s atmosphere c. a meteorite similar in composition to rocks on Earth that may contain carbon compounds d. the rarest type of meteorite 12 meteorite . e. a meteoroid or any part of a meteoroid that is left when it hits Earth 13 stony-iron meteorite . f. a meteorite with a distinctive metallic appearance Types of Meteorites Fifty thousand years ago, a giant fireball streaked across the North American sky. It struck the earth in what is now northern Arizona, exploding with the force of 2 ½ million tons of TNT. 14. Why are the oldest meteorites important? • Because they may be 100 million years older than Earth and its moon, and thus may provide information about how the early solar system formed. Handout 30-3 Star Groups 1. What is a galaxy? • a large-scale group of stars, gas, and dust bound together by gravity 2. What is the diameter of the Milky Way? • about 100,000 light-years 3-6 Matching 3. elliptical galaxy a. varies from almost spherical to a stretched out football in shape and has a bright center 4. barred spiral galaxy b. has a nucleus of bright stars and flattened arms that circle around the nucleus c. has a no particular shape and may have a low total mass 5. irregular galaxy 6. spiral galaxy d. has a straight bar of stars that runs through the center Types of Galaxies 7. What does the Milky Way look like in the night sky? • a cloudlike band that stretches across the sky 8. How is the sun related to the Milky Way? • It is one of hundreds of billions of stars in the Milky Way. 9. How long does it take the sun to orbit around the Milky Way? • About 225 million years 10. What are the closest neighbors to the Milky Way? • Two irregular galaxies called the Large Magellanic Cloud and the Small Magellanic Cloud 11. How far from Earth are the Milky Way’s closest neighbors? • More than 170,000 light-years away from earth THE END???